Evaluation of infectious hematopoietic necrosis, infectious pancreatic necrosis and viral hemorrhagic septicemia viruses in Iranian and imported rainbow trout eggs: A cross sectional study



BACKGROUND: Infectious hematopoietic necrosis (IHN), viral hemorrhagic septicemia (VHS) and infectious pancreatic necrosis (IPN) as important viral diseases of salmonids, especially rainbow trout can be led to mass mortality among cultured fish. OBJECTIVES: The aim of the present study was to show if IHN, IPN and VHS viruses can be detected in Iranian and imported rainbow trout eyed eggs and to compare their abundances among the hatcheries of 3 regions (Farsan, Koohrang and Lordegan) in Chaharmahal va Bakhtyari Province. METHODS: In each area, three hatcheries were selected, 20 eyed eggs were randomly sampled from each farm. The samples were transferred into the sterile tubes and identified by reverse transcriptase -PCR. Meanwhile, physicochemical factors were recorded for each fish. RESULTS: While total infection rate in eggs was 23.3 %, the level of infection for IPN, IHN and VHS was 12.5%, 10% and 0.83%, respectively. In this respect, maximum and minimum frequency were observed in Farsan (19.15%) and Koohrang (0.83%). Comparison of the infected of eggs, based on their origin, showed that the infection rates in Iranian and imported eggs were 20% and 3.33%, respectively. CONCLUSIONS: The results revealed that rainbow trout eggs should be considered as major source for transmission of aquatic viruses. Hence, molecular identification of above mentioned viruses in rainbow trout eggs should be done.